Holography (from two ancient Greek words — ὅλος — complete + γράφω — write) — a technology to record, regenerate and transform wave fields of optical radiation; a unique method of photography that uses a laser to register and then regenerate images of objects.
There are some extraordinary features of holograms:
a hologram retains phase of light waves in addition to their intensity;
a flat hologram can easily produce shaped or “3D” image;
unlike a photograph, when you look at a hologram, you should not expect to see a likeness of the object, but rather the diffraction pattern of the object;
unlike a photograph, when a hologram is cut in pieces, the whole scene can still be seen in each piece;
holograms can also be entirely computer-generated and show objects that never existed.
Some of the features are shown on the video below:
